OREASTERIDAE Fisher 1908

Yiu, Sam King Fung & Mah, Christopher L., 2024, New Ecological Observations and Occurrence for Asteroidea and Echinoidea in Hong Kong, Zootaxa 5526 (1), pp. 1-69 : 50

OREASTERIDAE Fisher 1908

Five species of Hong Kong oreasterids are reported herein as opposed to the four reported by Liao & Clark (1995). As discussed by Liao & Clark (1995) and elaborated upon below, there are many doubts regarding the occurrence of several Anthenea spp. as indicated. We report novel occurrences of several oreasterids from Hong Kong waters, such as Culcita novaeguineae , Pentaceraster alveolatus , and Pentaceraster sibogae , which are otherwise widely reported from tropical Indo-Pacific settings and from southern China by Liao & Clark (1995).

Oreasterids undergo a significant change in appearance as they become larger. At a size range of approximately R=5.0 mm to 30 to 50 mm, (this varies with species), many oreasterids, such as Culcita , possess a pentagonal to more weakly stellate, relatively planar and undecorated surface “goniasterid” like shape which changes to the more heavily armored and strongly arched form seen in large Oreasteridae . These smaller goniasterid-like forms can be difficult to associate with the larger body forms based purely on external appearance since intermediate characters are difficult to discern and colors change, sometimes dramatically. For example, the Atlantic Oreaster reticulatus changes from a dark mottled green and brown to bright red ( Hendler et al. 1995). Culcita novaeguineae is the best documented of these, changing from a pentagonal goniasterid-like form to a significantly large, mound-shape ( Kano et al. 1991). Multiple images on iNaturalist (e.g. https://www.inaturalist.org/observations/117293137) are potentially small forms of either Anthenea , Gymnanthenea or Pentaceraster but further data is required to confirm identification.